The effects of foot orthosis and low-dye tape on lower limb joint angles and moments during running in individuals with pes planus

BackgroundPes Planus or Flat feet is one of the most common lower limb abnormalities. When runners with this abnormality participate in recreational running, interventional therapies could help in pain alleviation and enhance performance. To determine the most effective treatment, however, a biomechanical examination of the effects of each treatment modality is required.Research questionThe aim of the present study was to investigate the effects of Foot Orthoses (FOs) and Low-Dye Tape (LDT) on lower limb joint angles and moments during running in individuals with pes planus.Methodskinematic and kinetic data of 20 young people with pes planus were measured during running in three conditions: (1) SHOD (2) with shoes and FOs (3) with shoes and LDT. One-way repeated measure ANOVA was used to investigate the impacts of the FOs and LDT on the lower limb joint angles and moments throughout the stance phase of the running cycle.ResultsThe results showed that FOs reduced ankle eversion compared to SHOD and LDT (P < 0.001) and decreased the dorsiflexion angle (P = 0.005) and the plantarflexor moment compared to the SHOD (P < 0.001). FOs increased knee adduction angle (P = 0.021) and knee external rotator moment (P < 0.001) compared to both conditions and increased knee extensor and abductor moments compared to SHOD (P < 0.001). At the hip joint, FOs only increased hip external rotation compared with the LDT condition (P = 0.031); and LDT increased hip extensor moment compared to SHOD and FOs (P = 0.037) and also increased hip adduction angle compared to SHOD (P = 0.037).SignificanceFOs with a medial wedge appears to increase the external knee adduction moment and knee adduction angles, which are risk factors for the development and progression of knee osteoarthritis. Further, usage of FOs seems to reduce the ankle joint role in propulsion as it impacts the ankle sagittal angles and moments.     

Calculation of joint moments following foot contact across two force plates

This study aimed to quantify the effect of combining the measurements from force plates when a subject's foot comes in contact with more than one force plate. A 3-Dimensional Gait Analysis (3DGA) was performed on a subject walking barefoot. Ten gait trials (good both) were captured where both subject's feet hit a single force plate. Then 20 gait trials (two force plates) were captured where either the right or left subject's foot was in contact with two force plates at a time. Kinematics were computed with VICON^® Plugin Gait and kinetics with a BodyLanguage^® (VICON, Oxford, UK) model that allowed the combination of force plate measurements. The kinetics traces from both sets of data were compared using variance component analysis. Results suggest that effects of how the moments were calculated were at most a third of those arising from stride to stride variability. This suggests that development of automated systems for determining foot contact coupled with arrays of more and smaller force plates than are commonly used might be useful to ensure the capture of good quality kinetic data in a wide range of patients.     

The development of sit-to-stand in typically developing children aged 4 to 12 years: Movement time,trunk and lower extremity joint angles,and joint moments

BackgroundSit-to-stand (STS) movement is an important transition movement for daily life. STS movement is typically seen in children aged 1 year and older. According to the motor development process, the ability of children in different age groups to perform STS movement would be different before they meet the mutuality. However, it is still unclear whether there are changes in the STS movement of growing children and adults.Research questionAre there any differences in the movement time, joint angles, and peak joint moments of STS in typically developing (TD) children?MethodsMotion analysis and the force plate system were used to analyze the STS movement in 77 healthy participants. All participants were asked to perform the STS movement using an adjustable bench with a self-selected pattern. Statistical analysis was done with respect to age (4–6, 7–9, 10–12, 18–25 years) and body height (1.00–1.20, 1.20–1.40, 1.40–1.60, 1.60–1.80 meters).ResultsChildren aged 4–6 years (or 1.0–1.20 m height) took less time to accomplish STS movement than adults (or 1.60–1.80 m height). Children aged 4–9 years performed STS movement by using more trunk and hip flexion and anterior pelvic tilt, but less knee flexion and ankle dorsiflexion than children aged 10–12 years and adults. At the final standing position, children aged 4–12 years exhibited more knee extension and more ankle plantar flexion than adults. In addition, children aged 4–12 years had more peak trunk-pelvic extension and less peak knee extension moments than adults.SignificanceDifferent strategies to achieve the STS task were found among children aged 4–12 years in terms of total movement time, joint angle, and joint moments. Adult-like kinematic and kinetic STS patterns were not seen in children up to 12 years old.     

The influence of stride-length on plantar foot-pressures and joint moments

Purpose

Joint moments have been acknowledged as key factors in understanding gait abnormalities. Gait velocity is further known to affect joint moments and foot pressures. Keeping gait velocity constant is thus a strategy to cancel out the influence of different preferred gait speed between groups. But even if gait velocity is controlled, individuals can choose different stride length–stride frequency combinations to cope with an imposed gait velocity.

Scope

To understand the influence of stride frequency–stride length on joint moments and plantar pressures.

Methods

Twenty healthy young adults had to cross an 8 m walkway with a walking speed of 1.3 m s⁻¹. The wooden walkway was equipped with a force and a pressure platform. While walking speed was kept constant each participant walked with five different imposed stride lengths (SL): preferred (SL0); with a decrease of 10% (SL − 10); with a decrease of 20% (SL − 20); with an increase of 10% (SL + 10) and with an increase of 20% (SF + 20).

Results

Ankle and knee joint moments significantly decreased with a decrease in SL. A significant (p < .05) lower peak pressure was achieved with a decreased SL under the heel, toes and midfoot.

Discussion/conclusion

The results showed that a change in stride lengths alters both, joint moments and foot pressures with clinically interesting indications. Redistribution of joint moments in the elderly for example might rather result from decreased SL than from age.     

The diabetic foot: Charcot joint and osteomyelitis

Foot problems are common causes of disability in diabetic patients with as many as 25% expected to develop severe foot or leg problems during their lifetimes. Although skin ulceration is the most frequent problem, bones may also be involved in two different clinical conditions: osteomyelitis and Charcot osteoarthropathy. Osteomyelitis causes complications in up to one third of diabetic foot infections and is due to direct contamination from a soft-tissue ulcer. Osteoarthropathy Charcot foot is a chronic and progressive disease of the bone and joints. Both osteomyelitis and Charcot joint are conditions with an increased risk of lower limb amputation, both may have a successful outcome when recognized and treated in the early stages. The major diagnostic difficulty is in distinguishing bone infection (osteomyelitis) from non-infectious neuropathic bony disorders as in osteoarthropathy Charcot foot. An additional difficulty is found when a bone infection superimposes a Charcot osteopathy. This condition, which can be clinically suspected when foot ulceration appears in Charcot foot, needs to be diagnosed because it implies a different therapeutic strategy. This article aims to summarize both these two clinical conditions and give indications to make a timely and correct diagnosis.     

The effects of anterior and posterior ankle-foot orthoses on sit-to-stand transfer performance in stroke patients

BackgroundNonarticulated and low-temperature thermoplastic ankle–foot orthoses (AFOs) have a semirigid design and are effective in improving the postural control mechanism (PCM) in individuals with poststroke hemiparesis. AFOs with an anterior leaf (AAFOs) are more often prescribed than are AFOs with a posterior leaf (PAFOs); however, the effects of AAFOs on the PCM during sit-to-stand transfer (STST) have not been explored.Research questionsDo AAFOs and PAFOs change the PCM differently during STST?MethodsA cross-sectional quasi-experimental design was adopted in this study. Fourteen individuals with poststroke hemiparesis (10 men and 4 women, aged between 38 and 71 years, stroke onset between 1 and 17 months) performed STST with shoes only, an AAFO with shoes, or a PAFO with shoes. Vertical ground reaction force (VGRF) and center-of-pressure (CoP) coordinates were collected using a pressure mat to calculate PCM parameters. A single-factor repeated measures analysis of variance was performed to answer the research question.Results(1) The weight-bearing percentage of the paretic leg was significantly lower when the participants wore a PAFO (p = 0.018) than when they wore an AAFO (p = 0.019) during the first 5 and 5–10 s after rising. (2) A small rate of change of the VGRF increment (dF/dT) was detected when participants wore AFOs, particularly AAFO. (3) The maximum mediolateral displacement of the CoP when standing up was significantly different among the three conditions (p = 0.012).SignificanceFor patients with poststroke hemiparesis, AAFO and PAFOs change the PCM during STST performance. Only AAFO improved the PCM possibly because of the rigidity and clearance of the heel region, which provide somatic sensory feedback. Therefore, rehabilitation professionals should educate hemiplegic patients who use AAFOs or PAFOs to perform dynamic daily tasks slowly for their safety.     

The immediate effects of sensorimotor foot orthoses on foot kinematics in healthy adults

BackgroundSensorimotor foot orthoses is an alternative concept, which in addition to mechanical effects, are designed to change muscle activation by altering sensory input to the plantar surface of the foot. However, there is little evidence of how these affect the kinematics of the foot during gait.Research questionThe aim of the study was to explore the immediate effect of calcaneal medial heel bars and retrocapital bars on foot kinematics during the stance phase of gait.MethodsKinematic data were collected from 32 healthy individuals using an eight camera motion capture system and a six-degrees-of-freedom multi-segment foot model in three different orthotic conditions; calcaneal medial heel bar, retrocapital bar, and no orthosis. Vector field statistical analysis was performed to explore the effect of the orthotic conditions over the kinematic time series curves during stance phase. Peak median and interquartile ranges were also reported during the different phases of stance.ResultsThe calcaneal medial bar significantly decreased rearfoot eversion for the majority of the stance phase and compensatory increased midfoot eversion during the entire stance phase compared to the no orthosis condition. The retrocapital bar rotated the foot externally significantly abducting the rearfoot for the entire stance phase and the midfoot for the majority of stance phase.SignificanceThe calcaneal medial heel bar and retrocapital bar significantly altered the foot kinematics in a way that may benefit patients with abnormal pronation and intoeing gait.     

Immediate effects of valgus bracing on knee joint moments during walking in knee-healthy individuals: Potential modifying effects of body height

BackgroundThe goal of valgus knee brace treatment is to reduce medial knee joint loading during walking, often indicated by external knee adduction moment (KAM) measures. However, existing healthy-subjects studies have been equivocal in demonstrating KAM reduction with valgus knee bracing.Research questionWhat are the immediate effects of valgus bracing at different tension levels on KAM during walking at a controlled speed and does body height modify the brace-KAM associations?MethodsData from 32 knee-healthy participants were analysed in this randomized crossover trial. Participants performed walking trials at controlled speed (1.3 ± 0.065 m/s) both with and without an Ossür Unloader One® brace. During the bracing condition, valgus tension was incrementally increased, from zero tension to normal tension and to maximum tolerable tension.ResultsValgus bracing minimally increased knee flexion at heel-strike (P < 0.001) in a dose-dependent manner and minimally reduced gait velocity (∼0.015m/s) across all tension levels. Valgus bracing, overall, did not significantly reduce the various KAM measures. However, brace use at maximal tension was associated with a 0.04Nm/kg (9.2 %) increase in first peak KAM amongst participants with a body height of 1.75 m and a 0.03Nm/kg (7.6 %) decrease in first peak KAM amongst participants with a body height of 1.55 m.SignificanceValgus bracing did not reduce the various KAM measures during walking; however, body height may play a moderating role. Given knee brace sizes vary more in circumference than length, this result may be due to the ratio between effective moment arm length relative to limb length. A deeper understanding of the potential neuro-biomechanical effects of valgus knee bracing and how these effects are potentially modified by body height may be critical to the design of effective knee braces.     

The effect of variation in knee center location estimates on net knee joint moments

To test the sensitivity of knee flexion-extension moment patterns to variation in estimates of the knee center location (KCL), inverse dynamics analysis was performed using three different KCLs for data collected from 18 healthy adult subjects who walked at five different speeds (25%, 50%, 75%, 100% and 125% of 0.785 statures.s< ?? opnbop ?? ?-1). The KCL, which was determined using data from static subject calibration trials, was varied in software by plus or minus 10 mm in the anteroposterior direction. The effect of this KCL variation on knee moments was similar across subjects and at all five walking speeds. The relative knee center variation effect, expressed as a percentage of the mean knee moment, was progressively greater at slower walking speeds, up to 123% of the first extensor peak at the slowest speed. The implication of these results is that, while KCL variation does not affect the general shape of the moment pattern at more natural walking speeds, it can change the sign of the moment-and thus the interpretation-when the moment magnitude is small (e.g. at the very slow speeds used by some patients). When knee moments are of magnitudes less than or equal to the KCL variation effect, one cannot confidently interpret them as representing either a net flexor or extensor knee control strategy. Copyright 1998 Elsevier Science B.V.     

The effect of foot structure on 1st metatarsophalangeal joint flexibility and hallucal loading

The purpose of our study was to examine 1st metatarsophalangeal (MTP) joint motion and flexibility and plantar loads in individuals with high, normal and low arch foot structures. Asymptomatic individuals (n = 61), with high, normal and low arches participated in this study. Foot structure was quantified using malleolar valgus index (MVI) and arch height index (AHI). First MTP joint flexibility was measured using a specially constructed jig. Peak pressure under the hallux, 1st and 2nd metatarsals during walking was assessed using a pedobarograph. A one-way ANOVA with Bonferroni-adjusted post hoc comparisons was used to assess between-group differences in MVI, AHI, early and late 1st MTP joint flexibility in sitting and standing, peak dorsiflexion (DF), and peak pressure under the hallux, 1st and 2nd metatarsals. Stepwise linear regression was used to identify predictors of hallucal loading. Significant between-group differences were found in MVI (F_2,56 = 15.4, p < 0.01), 1st MTP late flexibility in sitting (F_2,57 = 3.7, p = 0.03), and standing (F_2,57 = 3.7, p = 0.03). Post hoc comparisons demonstrated that 1st MTP late flexibility in sitting was significantly higher in individuals with low arch compared to high arch structure, and that 1st MTP late flexibility in standing was significantly higher in individuals with low arch compared to normal arch structure. Stepwise regression analysis indicated that MVI and 1st MTP joint early flexibility in sitting explain about 20% of the variance in hallucal peak pressure. Our results provide objective evidence indicating that individuals with low arches show increased 1st MTP joint late flexibility compared to individuals with normal arch structure, and that hindfoot alignment and 1st MTP joint flexibility affect hallucal loading.     

关节镜辅助下足踝关节融合术

目的探讨关节镜辅助下足踝关节融合术的方法与疗效。方法2001年1月-2004年7月，采用关节镜辅助下踝关节融合术13例，距舟关节融合术8例。男15例，女6例；年龄32—68岁，平均41岁。其中踝关节粉碎性骨折伴创伤性骨关节炎6例，地方性大骨节病7例，距舟关节炎8例；左足9例，右足12例。镜下清除踝关节和距舟关节增生肥厚的滑膜和纤维瘢痕组织，磨削骨赘，切除胫骨端、距骨穹隆和内外侧踝穴的软骨和软骨下骨，进行自体骨植骨。为保证骨对骨的密切接触需进行内固定。结果术后均获得随访，时间6～38个月，平均10个月。术后关节无肿胀和疼痛，行走步态和功能明显改善，X线片显示骨性融合。结论关节镜辅助下进行踝关节和距舟关节融合，不仅创伤小、视野清晰、操作简便，而且不破坏周围结构，有利于融合并保留踝穴轮廓。     

On the expression of joint moments during gait

The purpose of the current study was to examine the effect of different reference frames on lower limb joint moments during gait with a view to identifying a recommended convention for clinical purposes. Data were collected from 10 subjects (nine able-bodied adults and one child with diplegic cerebral palsy) whilst walking at a self-selected speed. Calculations utilised a three-dimensional inverse dynamics model. For each joint, moments were expressed in four different reference frames. Three of the frames were orthogonal: laboratory frame; anatomical frame of proximal segment; anatomical frame of distal segment. The fourth reference frame was a non-orthogonal joint coordinate system (JCS). Significant differences in the joint moment profiles during gait were found with alternative references frames. This was apparent primarily for the transverse plane joint moments for able-bodied adult gait. For the pathological gait pattern presented, there were also marked differences in the frontal plane joint moments and more subtle ones in the sagittal plane. Whilst it is recognised that all possible reference frames for the expression of the net moment vector are mathematically valid, a decision needs to be made as to which one is more clinically useful. It is proposed that the non-orthogonal JCS is most logical on the basis of what, biomechanically, the joint moment actually represents.     

The effects of joint angle and reliability on knee proprioception

PURPOSE: The purpose of this study was to examine the reliability and effects of knee angle on the detection and subsequent response to passive knee movement. METHODS: Twenty college-aged male and 20 female volunteers were evaluated for proprioception by a newly developed perturbation test. Subjects were in a prone position on an isokinetic chair with their right lower leg attached to a freely moving resistance adapter. The knee was placed in a starting position of 15, 30, or 60 degrees of flexion. While relaxed, the knee was dropped into extension, and the subjects were instructed to "catch their leg" when movement was perceived. Five trials were completed at each angle, in a random order. An electrogoniometer was secured to the lateral portion of the knee in order to measure angular displacement after perturbation in two specific phases: detection (displacement from leg release to movement cessation) and response (displacement from movement cessation to peak knee flexion). A three-factor ANOVA (two repeated factors (knee angle and proprioception phase) and one between factor (gender)) was performed on the average and standard deviation of the five trials for significant main effects and interactions. RESULTS: The results demonstrated a significant phase by angle interaction, and no gender effect. It was shown that at a more extended knee joint position (15 degrees), significantly less knee movement occurred before perception, followed by a greater response, than in a more flexed position (30 and 60 degrees). CONCLUSION: The major findings of this study suggest that the detection of passive knee movement, and the subsequent voluntary response, may be dependent on joint angle. Considerations of the present method for proprioception assessment are warranted to enhance test-retest reliability.     

Immediate effects of therapeutic music on loaded sit-to-stand movement in children with spastic diplegia

The effects of patterned sensory enhancement (PSE) music on muscle power and movement control in children with spastic diplegia (SD) during loaded sit-to-stand (LSTS) were investigated. Twenty-three children with SD aged 5 to 12 years were recruited. Individualized PSE was composed by a music therapist based on each subject's sit-to-stand (STS) movement with 50% 1-repetition maximum load. Each subject performed LSTS continuously for eight repetitions under randomly assigned music or no-music (Control) conditions while the kinematic and kinetic data were measured simultaneously. For the music condition, PSE music was played only during the first five repetitions (PSE condition), and the following three repetitions were referred to as the Continuation condition. Paired t- or Wilcoxon signed rank tests were used to compare the variables between the PSE and Control conditions, and between the Continuation and Control conditions. Compared to the Control condition, greater peak knee extensor power (P=0.009), greater total extensor power (P=0.015), and better center-of-mass smoothness (P=0.01), but less movement time (P=0.003) were found in the PSE condition. Significant effects of the PSE music on the above variables were also found for Continuation condition. The current results showed that individualized PSE music helped improve the performance of LSTS in children with SD. The associated biomechanical features also continued to exist in subsequent movement cycles after the music had ceased. These findings suggest that therapy using LSTS combined with PSE music may be beneficial for rehabilitating children with SD.     

The effects of walking,running, and shoe size on foot volumetrics

Objectives. The objective of this study was to investigate the effects of walking and running on foot volumetrics, and its relationship between measured foot size and preferred shoe size.Design. This study was a single-group, repeated measures design. Twenty-eight physical therapy students participated in the testing.Methods. Following 10 min of supine rest, a pre-exercise volumetric measurement of the right leg was obtained. Shoe size and foot length measurements were taken. Subjects were randomly assigned to a treatment condition (walking or running). The treadmill speed was set at a comfortable pace for each participant during exercise. Foot volume measurements were taken after the exercise. Subjects returned the next week to participate in the second condition.Results. Paired t-tests were used to compare differences in outcome variables. Significant increases in fluid volumes were noted within groups after walking (2%) and running (3%) and between groups in the post-walk and post-run values (1.7%). A weak positive correlation was noted between changes in volume during running and the measured difference between foot size and shoe size (r=0.39; p=0.038).Conclusions. Treadmill running for 10 min may lead to significantly greater foot volume compared to treadmill walking for the same period. Results also demonstrate that the greater the measured difference between shoe size and foot size, the greater the foot volume after running.     

Estimation of muscle forces and joint moments using a forward-inverse dynamics model

PURPOSE: This paper presents a forward dynamic neuromusculoskeletal model that can be used to estimate and predict joint moments and muscle forces. It uses EMG signals as inputs to the model, and joint moments predicted are verified through inverse dynamics. The aim of the model is to estimate or predict muscle forces about a joint, which can be used to estimate the corresponding joint compressive forces, and/or ligament forces in healthy and impaired subjects, based on the way they activate their muscles. METHODS: The estimation of joint moments requires three steps. In the first step, muscle activation dynamics govern the transformation from the EMG signal to a measure of muscle activation--a time-varying parameter between 0 and 1. In the second step, muscle contraction dynamics characterize how muscle activations are transformed into muscle forces. The final step requires a model of the musculoskeletal geometry to transform muscle forces to joint moments. Each of these steps involves complex, nonlinear relationships. RESULTS: An application is provided to demonstrate how this model can be used to study the forces in the healthy ankle during dynamometer trials and during gait. The model-predicted estimates of joint moment were found to match experimentally determined values closely. CONCLUSION: Neuromusculoskeletal models that use EMG as inputs can be employed to accurately estimate joint moments. The muscle forces predicted from these models can be used to better understand tissue loading in joints, and to provide in vivo estimates of tensile ligament forces and compressive cartilage loads during dynamic tasks. This tool has great potential for aiding in the study of injury mechanisms in sports.     

Influence of coronal and sagittal prosthetic foot alignment on socket reaction moments in transtibial prostheses during walking

BackgroundThe socket reaction moment (SRM) has been reported to change because of alignment changes in transtibial prosthetic sockets. However, the influence of prosthetic foot alignment on SRM remains unclear.Research questionAre SRMs predictable from alignment changes of prosthetic feet?MethodsTen users of transtibial prostheses participated in this study. Under five alignment conditions (3 ° plantarflexion and dorsiflexion, 6 ° inversion and eversion, and baseline alignment), temporal-spatial parameters and sagittal and coronal SRMs were measured during walking. Cadence, walking speed, step time, single support time, and step length were compared. The maximum/minimum SRM, % stance (timing) of the maximum/minimum SRM, Zero-cross, and SRMs at 5 %, 20 %, and 75 % stance were extracted and compared. Repeated measures analysis of variance or Friedman tests, and linear regression analyses were conducted for statistical analyses (i.e., alignment conditions as independent variables and SRM parameters as dependent variables).ResultsThe SRMs at 5%, 20 %, and 75 % stance showed significant differences under coronal angular changes. The minimum SRM, % stance of the minimum/maximum SRM, and Zero-cross showed significant differences under sagittal alignment changes. In linear regression analysis, the minimum SRM, % stance of the minimum/maximum SRM, SRM at 20 % stance, and Zero-cross were significant dependent variables in the sagittal plane. The maximum/minimum SRM, SRM at 20 % and 75 % stance, and % stance of the minimum SRM were significant dependent variables in the coronal plane.SignificanceThe results indicated that the changes in prosthetic feet angles may predict the magnitude of SRM (maximum/minimum SRM, SRM at 20 % and 75 % stance) in the coronal plane, and the timing of SRM (Zero-cross, % stance of the maximum/minimum SRM) in the sagittal plane. These findings suggest that the SRM may be useful for evaluating foot alignment in transtibial prostheses.     

Examination of formula for enhanced dynamic wedge factors in symmetric and asymmetric fields

We proposed a formula for the enhanced dynamic wedge (EDW) factor in the half-field (HF) that combined the formula proposed by Liu et al. in 1998 and their formula in 2003. When the EDW was used for irradiation to the tangent line of the HF breast, the values calculated by our formula and the measured values were consistent within 0.5%. We showed that our proposed formula was useful, easy to use, and more accurate than the conventional formula. The purpose of this study was to examine the available range of the wedge factor of symmetrical and asymmetric EDW calculated by our formula. As a result of the examination, the values calculated by our formula and the measured values were consistent within 2% except for highly asymmetric EDW. We created a spreadsheet to calculate the wedge factor easily and accurately. We will examine the reason why the calculated and measured values were greater than 2%, and improve our formula so that it can be used in a wider range.     

MR imaging of inflammatory joint diseases of the foot and ankle

Pain affecting the foot and ankle is a common complaint frequently attributable to inflammatory joint diseases. Although conventional radiography is regarded as the initial step in the diagnostic investigation, MR imaging may contribute to further evaluation of these patients due to the direct visualization of the inflammatory soft tissue formed in the disease and its effects on bone, cartilage and para-articular structures. The high spatial resolution of MR imaging combined with tissue characterization often allows initial detection of inflammatory joint abnormalities at a stage that precedes radiographic evaluation. The typical MR appearance of certain inflammatory joint disorders may be helpful in narrowing the wide differential diagnosis. Furthermore, MR imaging can be used for an exact assessment of the extent of the disorder as well as its complications. Accurate diagnostic information can guide the clinician in further diagnostic tests and implementation of proper therapeutic treatment. Received: 12 November 1998 Revision requested: 12 February, 10 June 1999 Revision received: 14 September 1999 Accepted: 20 September 1999